Type slug mounting for high speed chain printer

ABSTRACT

A HIGH SPEED CHAIN-TYPE PRINTER HAVING A PLURALITY OF RELATIVELY WIDE, MULTI-CHARACTER TYPE SLUGS MOUNTED ON THE PRINTING CARRIER IN CLOSE PROXIMITY TO EACH OTHER. THE CARRIER IS AN ENDLESS TOOTHED BELT DRIVEN BY GREARS IN MESH WITH ITS TEETH. THE SLUGS ARE MOUNTED ON THE BELT BY CYLINDRICAL PINS STRADDLING SELECTED TEETH ON THE BELT. SPRING FINGERS ARE ALSO PROVIDED AT THE PRINT STATION TO URGE THE TYPE SLUGS AGAINST A BACK-UP MEANS.

Nov. 23, 1971 D: J. RIPPLE ETAL.

TYPE SLUG MOUNTING FOR HIGH SPEED CHAIN PRINTER Filed March 10, 1970 8 N M l l 0 15 T DD R A N 0 M O I W EW if m mRN. M I mm W VS mm ow United States Patent 3,621,778 TYPE SLUG MOUNTING FOR HIGH SPEED CHAIN PRINTER David J. Ripple and Joseph N. Bond, Commack, N.Y.,

assignors to Potter Instrument Company, Inc., Plainview, N.Y.

Continuation of application Ser. No. 778,631, Nov. 25, 1968. This application Mar. 10, 1970, Ser. No. 17,043 Int. Cl. B41j 1/20 US. Cl. 10193 15 Claims ABSTRACT OF THE DISCLOSURE A high speed chain-type printer having a plurality of relatively wide, multi-character type slugs mounted on the print type carrier in close proximity to each other. The carrier is an endless toothed belt driven by gears in mesh with its teeth. The slugs are mounted on the belt by cylindrical pins straddling selected teeth on the belt. Spring fingers are also provided at the print station to urge the type slugs against a back-up means.

REFERENCE TO RELATED APPLICATION This application is a continuation of application Ser. No. 778,631, filed Nov. 25, 1968, now abandoned.

BACKGROUND OF THE INVENTION The present invention generally relates to a chain-type high speed printer, and more particularly to a high speed printer provided with multi-character type slugs.

Chain-type high speed printers are used in the data processing industry to visually reproduce stored information. Examples of such high speed printers are illustrated in US. Pats. Nos. 3,353,483; 3,381,611; 3,379,125; and copending patent application Serial No. 509,501, filed Nov. 24, 196 5, and assigned to the same assignee of the present invention. In these chain-type printers, a plurality of type slugs are rigidly mounted on an endless, toothed belt driven between a spaced idler and driving gear. A plurality of print hammers positioned adjacent the belt are adapted to be individually actuated by separate electromagnets to drive paper interleaved between the belt and hammers against selected slugs, to imprint a raised character carried by the slug on the paper. Backup means, such as a back-up bar or a pair of back-up plates are positioned behind the slugs to support them during impact by the print hammer.

The type slugs used in the conventional chain-type high speed printer are narrow in width, permitting them to achieve an are around the gears driving the belt. A relatively wide slug fixed to the belt would either rigidity the belt so that it could not turn around the gears or it would increase the tension on the belt and cause high local stresses resulting in wear and degradation. On the other hand, by restricting the width of the type slug, only one character can be mounted on it. This necessitates use of a large number of individual, narrow slugs, increasing the cost of the printer.

Furthermore, the narrow slugs must be sufficiently spaced along the belt to provide the necessary turning flexibility, and hence, they are relatively unstable as they pass the print line. Upon impact, the type slugs tend to bounce off the back-up means and turn, causing the paper to be smudged or double characters to be printed, regardless of the proximity of the type slugs and belt to the back-up means.

SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide a type slug mounting for a high speed, chain-type printer,

3,621,778 Patented Nov. 23, 1971 which enables a plurality of relatively wide, multi-character type slugs to be mounted on the type carrier in close proximity to each other, reducing the cost of the printer and providing lateral stability of the slugs to minimize their deflection during printing.

Another object of this invention is to provide independent restraining means cooperating with the type slug to urge it.against the back-up means during printing as a further aid in minimizing the tendency of the type slug to deflect after impact.

Briefly, these objects are accomplished by mounting the slug about a tooth of a type carrying belt by the use of cylindrical pins inserted through upper and lower backing flanges provided on the slug. Two pins are inserted in each flange equi-distant from the center line of the slug. The pins inserted through each flange are spaced a sufficient distance apart to straddle a tooth on the belt, thereby locking the slug on the belt, but providing rolling contact with the tooth so the belt can turn around the idler and driving gears. Spring fingers are provided for contact with the slug, as they pass through the printing station, to push the slug against the back-up means to aid in minimizing their deflection upon impact.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawing, in which:

BRIEF DESCRIPTION OF DRAWING FIG. 1 is a perspective view of component parts of a high speed printer as they relate to the structure of this invention, with certain portions broken away for purposes of clarity;

FIG. 2 is a cross-sectional view taken substantially along the plane indicated by line 22 of FIG. 1;

FIG. 3 is a cross-sectional view taken substantially along the plane indicated by line 3-3- of FIG. 2;

FIG. 4 is a fragmentary top plan view of one end of the printer structure illustrated in FIG. 1, and illustrating the manner in which a type slug mounted on the type carrier travels around one of the gears driving the carrier;

FIG. 5 is a perspective view of the type slug mounted on the printer structure; and

FIG. 6 is a cross-sectional view of a slightly modified form of one of the component parts of the printer.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the drawing wherein like numerals indicate like elements throughout the several views, FIG. 1 shows a chain-type high speed printer, generally identi fied by the numeral 10. Printer 10 includes an endless timing belt 12, whose function is described in greater detail in the above-identified copending patent application Ser. No. 509,501. Belt 12 has teeth 14 equally spaced along its back surface. Teeth 14 mesh with teeth 16, in a non-slipping manner, on both a driven gear 18 and an idler gear 20. An electric motor (not shown) connected directly to the gear 18 by a shaft 24, drives the gears.

A plurality of type-carrying slugs, such as illustrated by slugs 26 and 28 provided with raised characters 32, are supported on belt 12. The type slugs are carried past a print station 33 and slide along a pair of back-up plates 34, 35, which provide support for the slugs during impact by one of a plurality of print hammers, generally indicated by the numeral 36. Ordinarily, during operation of the printer 10, a printing medium such as an elongated strip of paper 37 (FIG. 2), usually with interleaved carbon and copysheets, is conveyed in step fashion between the hammers 36 and the type slugs 26 and 28 at print station 33.

The line traversed by the raised characters 32 between the hammers 36 and the back-up plates 34, 35, is commonly referred to as the printing line. A pair of guide plates 38, 40 (FIGS. 1 and 2) are provided in sliding contact with the top and the bottom of the type slugs, respectively, to maintain the characters 32 centered along the printing line. Plates 38, 40 can be secured to the backup plates 34, 35, respectively, by any conventional fastening means.

Each of the printing hammers 36 is actuated individually by separate electromagents 42. Upon actuation of an electromagnet 42, its associated printing hammer 36, having a head 44 pivotal about an axis 46 (FIG. 2), will strike the printing medium 37 driving it against a predetermined one of the raised characters 32 to imprint the character on the printing medium.

Electromagnets 42 are actuated by control circuitry 48 fed information 49 from data processing equipment to actuate a hammer 36 when a desired character 32 is positioned for printing. The circuitry 48 is Well known in the art and does not form a part of this invention. Examples of suitable circuitry are disclosed in US. Pats. Nos. 3,353,483 and 3,220,343.

Heretofore, only one standard sized character 32 (0.070 inch wide x 0.100 inch high) could be mounted per slug. The slug was rigidly mounted on the belt 12 and consequently had to be extremely narrow in width and sufficiently spaced from an adjacent slug in order to permit belt 12 to achieve an are around gears 18 and 20. A relatively wide slug fixed to the belt would either rigidify the belt so it could not turn around the gears or it would increase the tension on the belt and cause high local stresses resulting in wear and degradation. This not only increased the cost of the printer 10, but rendered the slugs relatively unstable as they passed the printing line, often resulting in smudged or double character printing upon impact of the slugs.

These disadvantages are eliminated by the type slug mounting of this invention. As shown in FIGS. 1, 2, and 5, each of the type slugs 26 and 28 is provided with an upper and lower backing flange 50 and 52, resectively, overlying opposite edges of belt 12 and terminating in sliding engagement with back-up plates 34, 35, as the slugs pass along the printing line. A pair of cylindrical pins 54, 56 are inserted through upper flange 50 equi-distant from the vertical center line of the slug to straddle the upper end of a tooth 58 on belt 12. Pins 54, 56 are in rolling contact with tooth 58. Similarly, a pair of cylindrical pins 60, 62 are inserted through a lower flange 52 equi-distant from the vertical center line of the slug to straddle the lower end of tooth 58 (FIG. 3). Pins 60, 62 are also in rolling contact with tooth 58.

The cylindrical pins lock the slug to belt 12, but allow the slug to roll relative to the belt as the belt turns about gears 18 and 20, as shown in FIG. 4. Because of this mounting, relatively wide slugs can be supported on selected teeth of belt 12 in close proximity to each other along the length of the belt. The slug-to-slug gap can be minimal, thus minimizing deflection or turning of each slug during impact by a print hammer 36. The relatively wide character face of each slug enables more than one raised character 32 to be mounted per slug, thereby reducing the cost of the printer. For example, on a one-fifth pitch timing belt, having type slugs mounted on alternate teeth, two standard characters 32 could be mounted along the printing line at 0.200 inch centers or four standard characters could be mounted at 0.100 inch centers. In addition, the loose engagement of the cylindrical pins with the belt teeth enable guide plates 38, 40 to readily center characters 32 along the printing line. Also, only flat or rounded corners contact belt 12, increasing its life.

While the wide slugs disclosed in this invention are relatively stable and rigidify belt 12, it may also be desirable to insure that they are held in sliding engagement with the back-up plates 34, 35 during printing. If small spaces develop between the slugs and back-up plates, the slugs will tend to bounce off the back-up bar and turn.

Therefore, shoulders 64, 66 (FIG. 2) are provided adjacent the top and bottom front edges of each type slug. A resilient retaining strip 68, substantially L-shaped in cross-section, is mounted on each guide plate 38, 40 by conventional fasteners. The vertical legs of strips 68 include spring fingers 70 abutting shoulders 64, 66 to resiliently urge each slug into sliding engagement with back-up plates 34, 35 and retain them against the plates during impact by a print hammer 36.

Alternatively, as shown in FIG. 6, each resilient retaining strip 68 can urge a bar 72, carried by springs fingers 70, into engagement with the slugs to retain them against the back-up plates 34, 35. Bars 72 can have curved sides to permit easy entrance of the slugs into print station 33. In either case, the slugs are prevented from rebounding after impact.

I claim:

1. In a high speed printer apparatus, the combination comprising:

a printing type carrier of the chain type adapted to support and to move a plurality of printing type slugs, a plurality of printing type slugs supported on said carrier in close proximity to each other and each having more than one raised print character thereon along a printing line, said printing type carrier including an endless belt having a plurality of spaced teeth along one surface thereof,

gear means having teeth cooperating with the teeth on said endless belt for driving said endless belt past an imprint station positioned at a fixed point relative to said belt, said imprint station including at least one print hammer means having a head for impact with raised print characters on said slugs,

control circuitry to operate said hammer means when a character on a predetermined slug is in a printing position at said imprint station,

back-up means positioned adjacent said type carrier to support each said type slug during impact by said hammer head,

each of said type slugs including an upper flange and a lower flange overlying opposite edges of said belt,

said type characters being in a single row alignment along said printing line on a front face of each respective slug, and

means carried by each of said upper and lower flanges for pivotally retaining each slug on said belt in rolling contact with a tooth thereof and oriented with said front face parallel to the plane in which said belt moves past said imprint station.

2. In a high speed printer apparatus as set forth in claim 1 wherein the raised print characters on each of said type slugs are substantially 0.07 inch wide mounted on centers spaced between 0.1 inch and 0.2 inch.

3. In a high speed printer apparatus having:

a printing type carrier of the chain type adapted to support and move a plurality of printing type slugs having at least one raised print character thereon along a printing line, said type carrier including an endless belt having a plurality of spaced teeth along one surface thereof,

at least one print hammer means having a head for impact with said raised print characters on said slugs,

control circuitry to operate said hammer means when a character on a predetermined slug is in a printing position, and

back-up means positioned adjacent said type carrier to support said type slug during impact by said hammer head, the improvement comprising:

each of said type slugs including an upper flange and a lgwer flange overlying opposed edges of said belt, an

means carried by each of said upper and lower flanges for locking each slug on said belt in rolling contact with a tooth, said locking means including a pair of cylindrical pins carried by each of said upper and lower flanges straddling said tooth.

4. In a high speed printer apparatus as set forth in claim 3, wherein each of said type slugs has more than one raised print character mounted thereon along said printing line.

5. In a high speed printer apparatus as set forth in claim 4 wherein each of said pins is equi-distant from the center line of said slug.

l6. In a high speed printer apparatus as set forth in claim 5-, resilient means for urging each type slug against said back-up means as it passes along said printing line.

7. In a high speed printer apparatus as set forth in claim 6 wherein said resilient means includes a pair of resilient retaining strips, one of said retaining strips having a plurality of spring fingers in contact with the upper surface of each type slug as it passes along said printing line, and the other of said retaining strips having a plurality of spring fingers in contact with the lower surface of each type slug as it passes along said printing line.

8. In a high speed printer apparatus as set forth in claim 3, wherein each of said pins is equi-distant from the center line of said slug.

9. In a high speed printer apparatus as setforth in claim 8, resilient means for urging each type slug against said back-up means as it passes along said printing line.

10. In a high speed printer apparatus as set forth in claim 9 wherein said resilient means includes a pair of resilient retaining strips, one of said retaining strips having a plurality of spring fingers in contact with the upper surface of each type slug as it passes along said printing line, and the other of said retaining strips having a plurality of spring fingers in contact with the lower surface of each type slug as it passes along said printing line.

11. In a high speed printer apparatus having:

a printing type carrier of the chain type adapted to support and move a plurality of printing type slugs having at least one raised print character thereon along a printing line,

at least one print hammer means having a head for impact with said raised print characters on said slugs,

control circuitry to operate said hammer means when a character on a predetermined slug is in a printing position, and

back-up means positioned adjacent said type carrier to support said type slug during impact by said hammer head, the improvement comprising:

a plurality of type slugs supported on said carrier in close proximity to each other, each of said type slugs having more than one raised print character mounted thereon along said printing line, and

resilient means mounted on said back-up means for urging each type slug against said back-up means as the respective slug passes along said printing line.

'12. In a high speed printer apparatus as set forth in claim 11 wherein said resilient means includes a pair of resilient retaining strips, one of said retaining strips in contact with the upper surface of each type slug as it passes along said printing line, and the other of said retaining strips in contact with the lower surface of each type slug as it passes along said printing line, said retaining strips mounted to opposite ends of said back-up means above and below said type slugs as they pass said printing position for impact by said hammer head.

13. In a high speed printer in which a hammer impacts a type face as said type faces move along a print line, the combination comprising: an elongated endless belt, a series of uniformly spaced positioning means on said belt distributed longitudinally along at least a portion of said belt, a plurality of type slugs mounted on said belt and movable therewith along said print line, means including a turn-around for driving said endless belt and said slugs in an endless path along said print line and around said turn-around, each of said type slugs being relatively wide in the direction of travel of said belt and having a plurality of discrete type faces formed thereon arranged in a row extending in the direction of travel of said belt, each of said type slugs having means in a central region thereof securing such slug to said belt in a fixed longitudinal position with respect to said positioning means and in cooperative engagement therewith, said central region extending across the middle of said slugs perpendicular to the direction of travel of said belt, said securing means comprising elements lapping over the edges of said belt and extending behind said belt only at said central region so that the outer edges of said type slugs can separate from said belt as said belt passes around said turnaround, at least one print hammer having a head for impacting said print characters on said type slugs, and controller circuitry to operate said hammer when a predetermined character on a slug is in position to be impacted by said hammer head.

14. A high speed printer as recited in claim 13, wherein said elements comprise flanges extending over the edges of said belt and at least one pin extending from one of said flanges behind said belt at said central region.

15. In a high speed printer as recited in claim 13, wherein said positioning means comprises a series of uniformly spaced teeth on said belt distributed longitudinally along at least a portion of said belt.

References Cited UNITED STATES PATENTS 2,267,661 12/1941 Meyers 101111 3,041,964 7/1962 Simpson et a1. 101111 3,041,965 7/1962 Sasaki 101-1l1 3,142,249 7/1964 Sasaki 101111 3,379,125 4/1968 Antonucci 10193 3,379,126 4/1968 Staller 101111 3,399,619 9/1968 Sims 10193 3,402,657 9/1968 Potter et a1. 101-93 3,435,756 4/1969 Martin 10193 3,379,125 4/1968 Antonucci 10193 3,379,126 4/1968 Staller et a1. 101111 3,399,619 9/1968 Sims 10193 3,402,657 9/1968 Potter et a1 10193 WILLIAM B. PENN, Primary Examiner US. Cl. X.R.. 101111 

